From the viewpoint of geological development, the mechanisms of formation of oil-field waters in non-marine basins and their relation with oil-gas reservoirs are discussed briefly. Sedimentary basins differing in geol...From the viewpoint of geological development, the mechanisms of formation of oil-field waters in non-marine basins and their relation with oil-gas reservoirs are discussed briefly. Sedimentary basins differing in geological setting and physical geographical environment would lead to a diverse evolution of fossil lake basin water body in chemical composition in the process of formation, development and extinction by themselves, resulting in oil-field waters with complex; variable and characteristic compositious China's non-marine basins are mostly derived from fossil lake basins. The substantial petroleum-generating stage is highly expected during the development of these fossil lake basins. The production of hydrocarbons responsible for petroleum is always accompanied by the production of sedimentary water. As a result, oil-gas migration took place under the action of high-pressure water and led to the preferential accumulation in the surrounding geological structures as a girdle pattern. In the oil-gas-bearing basins where seeping water is abundant, oil-gas reservoir are found distributed mainly along the “intersection zone” -- the “erestal plane”between the “ fossil-dewatering” of sedimentary water and the “fossil-interpolation”of seeping water. Due to the influence of various factors and the geochemical reactions, oilfield waters in Chiua's non-marine basins have remarkable “ion differential” phenomenon. Based on the phenomenon four types of ion assemblages can be distinguished.展开更多
文摘From the viewpoint of geological development, the mechanisms of formation of oil-field waters in non-marine basins and their relation with oil-gas reservoirs are discussed briefly. Sedimentary basins differing in geological setting and physical geographical environment would lead to a diverse evolution of fossil lake basin water body in chemical composition in the process of formation, development and extinction by themselves, resulting in oil-field waters with complex; variable and characteristic compositious China's non-marine basins are mostly derived from fossil lake basins. The substantial petroleum-generating stage is highly expected during the development of these fossil lake basins. The production of hydrocarbons responsible for petroleum is always accompanied by the production of sedimentary water. As a result, oil-gas migration took place under the action of high-pressure water and led to the preferential accumulation in the surrounding geological structures as a girdle pattern. In the oil-gas-bearing basins where seeping water is abundant, oil-gas reservoir are found distributed mainly along the “intersection zone” -- the “erestal plane”between the “ fossil-dewatering” of sedimentary water and the “fossil-interpolation”of seeping water. Due to the influence of various factors and the geochemical reactions, oilfield waters in Chiua's non-marine basins have remarkable “ion differential” phenomenon. Based on the phenomenon four types of ion assemblages can be distinguished.